Using bandwidth allocation data to determine a breakdown of volte calls by amr coding mode

ABSTRACT

A breakdown of voice over long term evolution (VoLTE) calls by adaptive multi-rate (AMR) speech coding mode may be determined by accessing a plurality of call detail records (CDRs) containing information associated with a plurality of corresponding communication sessions established over a mobile telephony network, and filtering the plurality of CDRs to obtain a subset of CDRs that are associated with communication sessions that used VoLTE services. A data structure containing correlations between AMR speech coding modes and bandwidth values may be referenced in order to classify the CDRs of the subset of CDRs into groups of different AMR speech coding modes. In some embodiments, a capacity planning metric or a resource allocation metric may be recommended based at least in part on numbers of the CDRs in the subset of CDRs within each of the groups of the different AMR speech coding modes.

BACKGROUND

The fourth generation (4G) Long Term Evolution (LTE) standard is basedon packet-switched Internet Protocol (IP) networking. User equipments(UEs) that are 4G LTE-compliant are configured to provide voicecommunication capabilities over 4G LTE networks using a packet-basedprotocol, such as the voice over LTE (VoLTE) protocol. The VoLTEprotocol dedicates a particular speech codec for encoding and decodingaudio, thereby allowing two or more people to talk to each other over amobile telephony network using respective user equipment (UE). The3^(rd) Generation Partnership Project (3GPP) standard specifies speechcodecs that are to be used in the provisioning of VoLTE services overmobile telephony networks. Adaptive Multi-Rate (AMR) codec is one suchspeech codec that supports eight narrow band (i.e., 300 to 3400 Hertz(Hz)) speech coding modes with respective bit rates between 4.75 and12.2 kilobits per second (kbps). AMR Wideband (AMR-WB) is another speechcodec that supports nine wide band speech coding modes with respectivebit rates between 6.6 and 23.85 kbps. Table 1, below, provides the ninewide band speech coding modes supported by AMR-WB:

TABLE 1 AMR-WB Speech Coding Modes # of Bits in AMR-WB Coding Mode BitRate (kbps) 20 millisecond frame 0 6.6 132 1 8.85 177 2 12.65 253 314.25 285 4 15.85 317 5 18.25 365 6 19.85 397 7 23.05 461 8 23.85 477

AMR-WB provides improved speech quality, as compared to its narrowbandcounterpart (AMR), due to a wider frequency band of 50 to 7000 Hz, whichallows for new wideband audio technologies, such as high definition (HD)voice (sometimes referred to as “HD calling”). HD voice providesclearer-sounding calls and a decrease in background noise (e.g., streettraffic, wind, crowd noise, etc.) as compared to non-HD calling.Notwithstanding the carrier implementation of HD voice, however, not allVoLTE traffic is actually encoded/decoded using the available AMR-WBcodec. This is primarily due to the fact that not all UEs are capable ofutilizing the AMR-WB codec for speech encoding/decoding. For example, aVoLTE capable UE may call a landline or an older, legacy UE that isincapable of handling HD calling using the AMR-WB codec. As a result,some communication sessions end up being “renegotiated” to a narrowbandspeech codec (e.g., AMR) in order to establish a voice communicationsession. Carriers (or cellular network operators) that provide HD voiceservices typically lack insight into the proportion of their customers'calls that actually utilize AMR-WB (HD voice), which is a potentiallyvaluable insight.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description is set forth with reference to the accompanyingfigures, in which the left-most digit of a reference number identifiesthe figure in which the reference number first appears. The use of thesame reference numbers in different figures indicates similar oridentical items or features.

FIG. 1 illustrates an example cellular network environment forimplementing the techniques described herein, including techniques fordetermining a breakdown of voice over long term evolution (VoLTE) callsby adaptive multi-rate (AMR) speech coding mode.

FIG. 2 is a diagram illustrating example signaling within theenvironment of FIG. 1 during a VoLTE-based communication session.

FIG. 3 is a block diagram of an example architecture of a computingdevice configured to implement the techniques described herein.

FIG. 4 illustrates a flowchart of an example process for filtering calldetail records (CDRs) to obtain a subset of CDRs of interest thatpertain to VoLTE communication sessions.

FIG. 5 illustrates a flowchart of an example process for establishingcorrelations between AMR speech coding modes and bandwidth values.

DETAILED DESCRIPTION

Described herein are techniques and systems for determining a breakdownof voice over long term evolution (VoLTE) calls by adaptive multi-rate(AMR) speech coding mode. According to various embodiments, call detailrecords (CDRs) are obtained and stored by components of an evolvedpacket core (EPC) as communication sessions occur over a mobiletelephony network. The CDRs may contain information associated with aplurality of communication sessions established over the mobiletelephony network, including information pertaining to an amount ofbandwidth allocated for each of the communication sessions. The CDRs areaccessed and filtered to obtain a subset of the CDRs that are ultimatelyused for determining the breakdown of VoLTE calls by AMR speech codingmode. By filtering out irrelevant ones of the CDRs, a subset of CDRsthat are associated with communication sessions that used VoLTE servicesmay be obtained. A data structure containing correlations between AMRspeech coding modes and bandwidth values may be accessed to determinehow to classify the subset of CDRs into groups of different AMR speechcoding modes. Once classified, a number of CDRs within each of thegroups of different AMR speech coding modes may be determined. In someembodiments, a recommendation may be output based on the classifiedCDRs, such as a recommended capacity planning metric or a recommendedresource allocation metric.

In some embodiments, a process for determining a breakdown of VoLTEcalls by AMR speech coding mode includes accessing a plurality of CDRscontaining information associated with a plurality of correspondingcommunication sessions established over a mobile telephony network, andfiltering the plurality of CDRs to obtain a subset of CDRs that areassociated with communication sessions that used VoLTE services. Theprocess may proceed by referencing a data structure containingcorrelations between AMR speech coding modes and bandwidth values, andclassifying the CDRs of the subset of CDRs into groups of different AMRspeech coding modes based at least in part on the referencing. In someembodiments, the process includes recommending a capacity planningmetric or a resource allocation metric based at least in part on numbersof the CDRs in the subset of CDRs within each of the groups of thedifferent AMR speech coding modes.

Also disclosed herein are systems comprising one or more processors andone or more memories, as well as non-transitory computer-readable mediastoring computer-executable instructions that, when executed, by one ormore processors perform various acts and/or processes disclosed herein.

By determining a breakdown of VoLTE calls by AMR speech coding mode,resource allocation and/or capacity planning recommendations may bedetermined, which provides for configuring and/or planning a morereliable and efficient cellular network. For example, a carrier may gaininsight into the proportion or percentage of VoLTE calls that use theAMR-WB codec, and in response, the carrier can optimally plan for,and/or configure, a mobile telephony network to provide a requisiteamount of bandwidth to its customers, which, in turn, provides a morereliable and efficient mobile telephony network.

Example Environment

Although the techniques and systems disclosed herein are predominantlydescribed with respect to 4G LTE networks, it is to be appreciated thatthe techniques and systems described herein may be implemented in anyfuture cellular network (e.g., a fifth generation (5G) network). Thus,LTE, as it is used herein, may refer to current releases of LTEprotocol, or any future evolution of LTE.

FIG. 1 illustrates an example cellular network environment 100 thatsupports wireless communications between multiple user equipments (UEs),such as the UE 102 (e.g., a mobile device), and various networkcomponents of a mobile telephony network. FIG. 1 illustrates at leastsome of the components of a network architecture responsible forimplementing VoLTE services within the environment 100.

The UE 102 may be implemented as any suitable computing deviceconfigured to communicate over a wireless network, including, withoutlimitation, a mobile phone (e.g., a smart phone), a tablet computer, alaptop computer, a portable digital assistant (PDA), a wearable computer(e.g., electronic/smart glasses, a smart watch, fitness trackers, etc.),and/or any similar computing device. In accordance with variousembodiments described herein, the terms “wireless communication device”“wireless device,” “communication device,” “mobile device,” and “use′equipment WE)” may be used interchangeably herein to describe any UE 102capable of communicating over a wireless network and configured to VoLTEservices, as described herein. It is to be appreciated that the UE 102may be capable of communicating wirelessly using any suitable wirelesscommunications/data technology, protocol, or standard, such as GlobalSystem for Mobile Communications (GSM), Time Division Multiple Access(TDMA), Universal Mobile Telecommunications System (UMTS),Evolution-Data Optimized (EVDO), Long Term Evolution (LTE), Advanced LTE(LTE+), Generic Access Network (GAN), Unlicensed Mobile Access (UMA),Code Division Multiple Access (CDMA), Orthogonal Frequency DivisionMultiple Access (OFDM), General Packet Radio Service (GPRS), EnhancedData GSM Environment (EDGE), Advanced Mobile Phone System (AMPS), HighSpeed Packet Access (HSPA), evolved HSPA (HSPA+), Voice over IP (VoIP),VoLTE, and/or any future IP-based network technology or evolution of anexisting IP-based network technology.

The UE 102 may be attached to a mobile telephony network through a basestation 104 (sometimes referred to as a “cell site 104”) that isconfigured to receive, process, and/or transmit traffic, such as voiceor video calls, audio, video, text (e.g., Short Message Service (SMS)),and/or other data, to be sent to and/or received from the UE 102. Insome embodiments, the base station 104 may comprise an eNodeB. The basestation 104 may communicate with the UE 102 over radio interfaces toform a radio access network (RAN) that is configured to employ anysuitable radio access technology (RAT), such as an LTE RAT, as well asone or more additional RAT types (e.g., legacy RATs, such as a 3G RAT,2G RAT, etc.). Accordingly, the base station 104 may be capable ofcommunicating wirelessly using any suitable wireless communications/datatechnology, protocol, or standard, such as GSM, TDMA, UMTS, EVDO, LTE,LTE+, GAN, UMA, CDMA, OFDM, GPRS, EDGE, AMPS, HSPA, HSPA+, VoIP, VoLTE,Institute of Electrical and Electronics Engineers (IEEE) 802.1xprotocols, WiMAX, wireless fidelity (Wi-Fi™), and/or any future IP-basednetwork technology or evolution of an existing IP-based networktechnology.

FIG. 1 illustrates a cellular network environment 100 that is configuredto enable both voice and data communication sessions for UEs, such asthe UE 102. In some embodiments, the environment 100 may include anevolved packet core (EPC) 106, a multimedia telephony (MMTel) and IPMultimedia Subsystem (IMS) architecture 108, and a packet datanetwork(s) 110. The network(s) 110 may include, without limitation, acable network, the Internet, a local area network, a mobile telephonenetwork, wide area networks and wireless networks, or any portion and/orcombination of such networks. In general, the EPC 106 is configured toprovide a LTE network, and the MMTel and IMS architecture 108 isconfigured to provide IP multimedia services.

When the UE 102 initiates a telephone call to call another UE, thetelephone call may be completed by the mobile telephony network usingVoLTE protocol. Initially, when the UE 102 is turned on, the UE 102attaches to the base station 104 to establish a radio link with the basestation 104. Once attached, the UE 102 is said to be “camped on” thecell that is associated with the base station 104. A voice communicationsession may be established using Session Initiation Protocol (SIP). SIPis a signaling protocol that can be used to establish, modify, andterminate multimedia sessions (e.g., a multimedia telephony call) overpacket networks, and to authenticate access to IMS-based services. A SIPINVITE method may be transmitted from the UE 102 that specifies, amongother things, the called party, a speech codec (e.g., AdaptiveMulti-Rate (AMR), AMR Wideband (AMR-WB), etc.) to use for the voicecommunication session. The network may establish a dedicated EPC, suchas the EPC 106, and a data radio bearer with a guaranteed bit rate (GBR)for voice traffic to/from the UE 102. FIG. 1 illustrates the SIPsignaling traffic 112 and voice traffic 114 over a dedicated bearer ofthe EPC 106.

In some embodiments, the mobile telephony network in the environment 100may use admission control to ensure that there are sufficient resources(e.g., physical radio equipment) and capacity for the network-requestedvoice bearer. This is why it is useful for a carrier to accurately planfor capacity and allocation of resources so that reliable service can beprovided to customers of the carrier's telephony services. Once the callis established, IP packets may be sent from the UE 102 to transmit voicedata over the mobile telephony network for a voice communicationsession.

The devices and/or networks shown in FIG. 1 are merely illustrative forexplanatory purposes, and in practice, there may be additional or fewerdevices and/or networks, different devices and/or networks, or thedevices and/or networks may be provided in different arrangements.Furthermore, the techniques described herein may be performed by asingle device, or a combination of devices, and the devices describedherein may be coupled together wirelessly or via a wired connection, ora combination thereof.

When a voice communication session is initiated by the UE 102 usingVoLTE protocol, components of the EPC 106, such as a packet data networkgateway (PGW), may collect information related to the voicecommunication session and may store this information in the form of calldetail records (CDRs) 116. As will be described in more detail belowwith reference to the following figures, the CDRs 116 may containinformation relating to a particular voice communication session,including, without limitation, information specifying the GBR bandwidththat is reserved (or negotiated) for the voice communication session, aRAT type value, and a Quality of Service Class Indicator (QCI) valuethat can be used to specify whether the communication session is usingVoLTE or another communication protocol.

According to various embodiments, a computing device(s) 118 may beconfigured (via one or more processors executing instructions stored inmemory of the computing device 118) to carry out a process 120 todetermine a breakdown of VoLTE calls by AMR speech coding modes that areutilized for the VoLTE calls.

At 122, the computing device 118 may access a plurality of CDRs 116 viathe network(s) 110 and may filter the CDRs 116 to obtain a subset of theCDRs 116 that are associated with communication sessions that used VoLTEservices. As noted above, the CDRs 116 may contain information such as aQCI value that, if set to a particular value (e.g., QCI=1), indicatesthat the communication session used VoLTE protocol. Thus, the filteringat 122 may comprise filtering the CDRs 116 according to a predeterminedQCI value indicative of VoLTE-based communication sessions. The CDRs 116may additionally include bandwidth information, such as an amount ofbandwidth (e.g., 49,000 bits per second (bps)) requested for thecorresponding communication sessions.

At 124, the computing device 118 may reference correlations 126 betweenAMR speech coding modes and bandwidth values maintained in a data store(data structure). The data structure containing the correlations (ormappings) 126 between AMR speech coding modes and bandwidth values maybe created and maintained in storage provided by the computing device118, or by an external (third party) resource accessible to thecomputing device 118. The correlations 126 may allow for translatingbandwidth information into AMR coding mode, which is useful because theparticular AMR coding mode established for a communication session maynot be readily apparent from the CDR 116 for that communication session.

At 128, the computing device 118 may classify the subset of CDRs 116relating to VoLTE communication sessions into groups of different AMRspeech coding modes based at least in part on the referencing of thecorrelations 126 at step 124.

At 130, the computing device 118 may output a recommendation comprisingat least one of a capacity planning metric or a resource allocationmetric based at least in part on numbers of the CDRs 116 that areclassified within each of the groups of the different AMR speech codingmodes. That is, the particular breakdown of VoLTE calls (e.g., whatproportion or percentage of VoLTE calls utilize AMR-WB speech codingmodes) may dictate the capacity planning and/or resource allocationmetrics. The resource allocation metric may comprise a recommendedamount of bandwidth to allocate to customers via available resources(e.g., physical radio equipment) and/or a recommended number ofresources to allocate for purposes of serving the customers. If thereare insufficient available resources for a projected demand fromcustomers of the mobile telephony network, a capacity planning metriccan be recommended that comprises a recommended number of resources toprovide or install for serving the customers. In this manner, theprocess 120 allows for configuring and/or planning a more reliable andefficient cellular network.

FIG. 2 is a diagram illustrating example signaling within theenvironment 100 of FIG. 1 during a VoLTE-based communication session.The signaling illustrated in FIG. 2 may be exchanged by variouscomponents of FIG. 1, including the UE 102, the base station 104, one ormore components of the EPC 106, and one or more components of the MMTeland IMS architecture 108. FIG. 2 is provided for purposes ofillustrating some of the information pertaining to a VoLTE communicationthat can be extracted and used for the techniques described herein.

For a VoLTE call to be initiated (e.g., the UE 102 calling another UE),an initial attachment procedure may be performed, which involves variousoperations including, but not limited to, determining that the LTEnetwork is voice-capable, identifying a Proxy-Call Session ControlFunction (P-CSCF) of the MMTel and IMS architecture 108, and performinga registration for a packet-switched LTE network. The call may beinitiated using a SIP INVITE method 200 transmitted via the EPC 106 forreceipt by a session border gateway (SBG) 202, which is forwarded to aserving-CSCF (S-CSCF) 204 of the MMTel and IMS architecture 108. TheS-CSCF 204 may generally be configured to provide routing services andto determine application servers (e.g., a telephony application server(TAS) 206) to which SIP messages are forwarded. The TAS 206 may beconfigured to provide various telephony services, such as call waiting,call forwarding, call conferencing, voicemail, and other types ofservices relating to communication sessions. The TAS 206 may return a183 session progress message 208 to the S-CSCF 204 in response to theSIP INVITE 200. The S-CSCF 204 may forward the 183 session progressmessage 208 to the SBG 202, which may forward the 183 session progressmessage 208 to the UE 102.

The SBG 202 may also transmit an acknowledgement reservation request(AAR) message 210 to a policy charging and rules function (PCRF) 212 ofthe EPC 106. The SBG 202 may extract information, such as quality ofservice (QoS) information, based on the interaction with the TAS 206,and may include the extracted information in the AAR message 210.Accordingly, the AAR message 210 may include a media componentdescription containing information, such as theMax-Requested-Bandwidth-UL (uplink), the Max-Requested-Bandwidth-DL(downlink), and other information describing the traffic flows beingrequested. For instance, a VoLTE call may request a Real-time TransportProtocol (RTP) flow or a RTP Control Protocol (RTCP) flow. RTP is astandardized packet format for delivering audio and video over IPnetworks. RTCP may be used to monitor transmission statistics and QoS,and may aid in the synchronization of multiple streams.

In general, the PCRF 212 creates and installs a set of charging and QoSrules for the media information received in the AAR message 210. ThePCRF 212 may answer the AAR message 210 by transmitting anauthentication and authorization answer (AAA) message 214 to the SBG202.

The PCRF 212 may further generate and transmit a Re-Authenticate-Request(RAR) message 216 to a PGW/policy and charging enforcement function(PCEF) 218 of the EPC 106. The RAR message 216 may cause theinstallation of the charging rules created by the PCRF 212. A portion ofan example charging rule corresponding to the RTP stream is provided inTable 2, below:

TABLE 2 Charging Rule for Audio RTP QCI 1 GBR-UL & GBR DL 38000 MBR-UL &MBR-DL 38000

In the example portion of the charging rule of Table 2, the GBRbandwidth reserved for the VoLTE call is 38000 bps for the RTP stream(both for the uplink (UL) and downlink (DL) direction). Furthermore, theQCI value of 1 indicates that the specified QoS corresponds to a QoSused for VoLTE calls.

The PCEF portion of the PGW/PCEF 218 may perform QoS and charging rulesanalysis using the set of charging and QoS rules received from the PCRF212 in the RAR message 216. The charging rules analysis may trigger thecreation of a dedicated EPC, such as the EPC 106, and a dedicated bearerwith a GBR bandwidth for voice traffic to/from the UE 102. As notedabove, FIG. 1 illustrates the SIP signaling traffic 112 and voicetraffic 114 over a dedicated bearer of the EPC 106.

In some embodiments, a create bearer request message 218 may be sentfrom the PGW/PCEF 218 to a mobility management entity (MME) 220configured to, among other things, perform signaling for establishingbearer channels dedicated for the communication session with the UE 102.Accordingly, the create bearer request message 218 may cause thecreation of the bearer traffic flow for the VoLTE call with the UE 102.The created bearer traffic flow may represent the traffic flow overwhich the voice call is implemented using VoLTE protocol. The amount ofbandwidth required for the created bearer traffic flow may be calculatedby the PGW portion of the PGW/PCEF 218 by aggregating the requestedbandwidth of all the GBR flows in the charging rules created by the PCRF212. This calculated bandwidth corresponds to the bandwidth allocatedfor the communication session on the RAN interface between the UE 102and the base station 104.

Additional messages relating to the establishment of the VoLTE call,including AAA messages, re-authentication answer (RAA) messages, and thelike, may be exchanged by the components of FIG. 2 to complete theestablishment of the VoLTE call. When the call is determined to beauthorized, a SIP 200 OK message 222 may be sent to the UE 102.

FIG. 3 is a block diagram of an example architecture of a computingdevice 118 configured to implement the techniques described herein. Asshown, the computing device 118 may include one or more processors 300and one or more forms of computer-readable memory 302. The computingdevice 118 may also include additional storage devices. Such additionalstorage may include removable storage 304 and/or non-removable storage306.

In various embodiments, the computer-readable memory 302 generallyincludes both volatile memory and non-volatile memory (e.g., randomaccess memory (RAM), read-only memory (ROM), erasable programmableread-only memory (EEPROM), Flash Memory, miniature hard drive, memorycard, optical storage, magnetic cassettes, magnetic tape, magnetic diskstorage or other magnetic storage devices, or any other medium). Thecomputer-readable memory 302 may also be described as computer storagemedia and may include volatile and nonvolatile, removable andnon-removable media implemented in any method or technology for storageof information, such as computer readable instructions, data structures,program modules, or other data. Computer-readable memory 302, as well asthe removable storage 304 and non-removable storage 306, are allexamples of computer-readable storage media. Computer-readable storagemedia include, but are not limited to, RAM, ROM, EEPROM, flash memory orother memory technology, compact disc read-only memory (CD-ROM), digitalversatile disks (DVD) or other optical storage, magnetic cassettes,magnetic tape, magnetic disk storage or other magnetic storage devices,or any other medium which can be used to store the desired informationand which can be accessed by the computing device 118. Any suchcomputer-readable storage media may be part of the computing device 118.

The computing device 118 may further include input devices 308,including, without limitation, a touch screen (e.g., touch, orproximity-based) display, physical buttons (e.g., keyboard or keypad), amicrophone, pointing devices (e.g., mouse, pen, stylus, etc.), or anyother suitable input devices 308 coupled communicatively to theprocessor(s) 300 and the computer-readable memory 302. The computingdevice 118 may further include output devices 310, including, withoutlimitation, a display, one or more LED indicators, speakers, a printer,or any other suitable output device coupled communicatively to theprocessor(s) 300 and the computer-readable memory 302.

The computing device 118 may further include communicationsconnection(s) 312 that allow the computing device 118 to communicatewith other computing devices 314 such as via the network(s) 110 ofFIG. 1. The communications connection(s) 312 may facilitate transmittingand receiving wireless and/or wired signals over any suitablecommunications/data technology, standard, or protocol, as describedabove, such as using a packet data network protocol.

In some embodiments, the computer-readable memory 302 may includevarious modules, programs, objects, components, data structures,routines, and the like that perform particular functions according tovarious embodiments. In some embodiments, the computer-readable memory302 includes a call tracer 316 configured to trace VoLTE calls byaccessing components of a mobile telephony network via the packet datanetwork(s) 110 and extracting portions of the signaling shown in FIG. 2in order to determine correlations between known AMR speech coding modesused for the VoLTE calls and the amount of bandwidth allocated for theVoLTE calls. In some embodiments, the call tracer 316 may, in theprocess of tracing a VoLTE call having a known AMR coding mode (e.g.,AMR-WB coding mode “8” corresponding to 23.85 kbps), extract, from thetrace, an amount of bandwidth allocated for the VoLTE call. As notedabove with reference to FIG. 2, the amount of bandwidth required for thecreated bearer traffic flow of the VoLTE call may be calculated by thePGW portion of the PGW/PCEF 218 by aggregating the requested bandwidthof all the GBR flows in the charging rules created by the PCRF 212. Thiscalculated bandwidth may be extracted by the call tracer 316 forpurposes of establishing correlations between the allocated bandwidthand the known AMR speech coding mode for the VoLTE call. Thesecorrelations 126 are shown in FIG. 3 as a table listing different AMRcoding modes mapped to corresponding bandwidth values. Thesecorrelations/mappings 126 may be and maintained in any suitable datastructure, such as a database or any similar data repository, store, orthe like, which may be accessed by the one or more processors 300, suchas when referencing the correlations by lookup queries.

The computer-readable memory 302 may further include a CDR access module318 configured to access the CDRs 116, which contain informationassociated with a plurality of communication sessions established over amobile telephony network of the environment 100 of FIG. 1. The CDRs 116may be maintained in a database or a similar data structure that allowsfor retrieving the CDRs 116 by the CDR access module 318 via thenetwork(s) 110.

The CDR access module 318 may further include a filter 320 configured tofilter the accessed CDRs 116 in order to obtain a subset of CDRs 116that are associated with communication sessions that used VoLTEservices. The filtering performed by the filter 320 may involve multiplefiltering steps that include filtering on various criteria, as will bedescribed in more detail below. For instance, the filter 320 may filteron a RAT type value that indicates the type of RAT utilized for thecommunication sessions, a QCI value that can be used for separatingVoLTE communication sessions from pure data sessions (i.e., non-voicecommunication sessions), call duration, bearer release information,and/or allocated bandwidth information.

The computer-readable memory 302 may further include a classifier 322configured to reference a database containing the correlations/mappings126 between AMR speech coding modes and bandwidth values, and toclassify the filtered set of CDRs 116 into groups of different AMRspeech coding modes based on the referenced correlations 126. Forexample, an individual CDR 116 that survives the filtering of the filter320 may specify that a bandwidth of 49000 bps was allocated for acorresponding VoLTE communication session. In this example, theclassifier 322 may reference the correlations 126 to lookup thebandwidth value of 49000 bps and to correlate the CDR 116 in question tothe AMR speech coding mode “8” for 23.85 kbps. Thus, the individual CDR116 in this example may be classified within a group corresponding to“AMR-WB 23.85,” although this label is merely illustrative and othergroup labels may be used for the different AMR speech coding modegroups. Additionally, or alternatively, the CDRs 116 may be classifiedaccording to the bandwidth that is allocated and/or requested for theVoLTE call prior to any referencing of the correlations/mappings 126.That is, the CDRs 116 may additionally, or alternatively, be classifiedby allocated or requested bandwidth. An example result of classifyingthe filtered CDRs 116 according to bandwidth requested for thecorresponding communication sessions is shown below in Table 3:

TABLE 3 Classified CDRs (VoLTE sessions) Max-Requested-Bandwidth-UL &Max-Requested- Count of Occurrences Bandwidth-DL (bps) (# of CDRs) 3700012852 39000 5911 38000 2703 49000 2328

By referencing the correlations 126 between AMR coding mode andbandwidth values, the bandwidth data in the left column of Table 3 canbe translated to a particular AMR speech coding mode (e.g., 49000bps=AMR WB 23.85 kbps), and thus, a breakdown of VoLTE communicationsessions by AMR speech coding mode can be obtained based on thebandwidth information associated with each CDR 116. Because VoLTEcommunication sessions can utilize both wide band and narrow band codecs(i.e., AMR-WB and AMR), an entity may gain insight into the proportionor percentage of VoLTE calls that utilize HD voice (i.e., AMR-WB codingmodes), which may be a valuable insight for the entity (e.g., acarrier).

The computer-readable memory 302 may further include a recommendationmodule 324 configured to recommend a capacity planning metric or aresource allocation metric based at least in part on numbers of the CDRs116 in the filtered subset of CDRs 116 that are classified within eachof the groups of the different AMR speech coding modes. In order tooutput a recommended resource allocation or capacity planning metric,the recommendation module 324 may be configured to access informationpertaining to resource-related metrics 326, such as data that indicatesa number of resources (e.g., physical radio equipment, such as basestation 104 equipment) required to provision a particular amount ofbandwidth for purposes of serving customers of a mobile telephonynetwork. In this sense, the recommendation module 324 may be configuredto analyze the numbers of classified CDRs 116 output by the classifier322 (e.g., proportions of VoLTE calls utilizing the AMR-WB codec versusproportions of VoLTE calls utilizing the narrowband AMR codec) topredict or project an amount of bandwidth needed to serve customers ofthe mobile telephony network over some future period of time (e.g., thenext several months). Based on this projected bandwidth demand over thefuture period of time, the recommendation module 324, with access to theresource-related metrics 326, may determine whether the existinginfrastructure of the cellular network can accommodate the anticipatedbandwidth demand, and/or whether a number of resources (e.g., radioequipment) can be allocated for providing that bandwidth demand. In thisscenario, the resource allocation metric recommended by therecommendation module 324 may comprise a particular number of resourcesto allocate for purposes of serving customers of a mobile telephonynetwork. Alternatively, if the recommendation module 324 determines thatthe number of available resources is insufficient for providing theprojected bandwidth, a capacity planning metric may be output by therecommendation module 324, which may comprise a particular number ofresources that are to be added to the existing infrastructure ofresources, which will accommodate the predicted bandwidth demand of thecustomers over the future period of time.

Example Processes

The processes described in this disclosure may be implemented by thearchitectures described herein, or by other architectures. Theseprocesses are illustrated as a collection of blocks in a logical flowgraph. Some of the blocks represent operations that can be implementedin hardware, software, or a combination thereof. In the context ofsoftware, the blocks represent computer-executable instructions storedon one or more computer-readable storage media that, when executed byone or more processors, perform the recited operations. Generally,computer-executable instructions include routines, programs, objects,components, data structures, and the like that perform particularfunctions or implement particular abstract data types. The order inwhich the operations are described is not intended to be construed as alimitation, and any number of the described blocks can be combined inany order or in parallel to implement the processes. It is understoodthat the following processes may be implemented on other architecturesas well.

FIG. 4 illustrates a flowchart of an example process 400 for filteringCDRs 116 to obtain a subset of CDRs 116 of interest that pertain toVoLTE communication sessions. The process 400 may represent asub-process of the process 120 described with reference to FIG. 1. Theprocess 400 may be implemented by the computing device(s) 118 via thefilter 320 to obtain the subset of CDRs 116 that are ultimatelyclassified by the classifier 322 at step 128 of the process 120.

At 402, CDRs 116 that have been accessed by the CDR access module 318may be filtered to obtain a subset of CDRs 116 that are associated withVoLTE communication sessions. The subset of CDRs 116 may also satisfyone or more additional criteria implemented by the filter 320 viasub-steps 404-412 of the process 400.

At 404, the filter 320 may select a first set of CDRs 116 that areassociated with communication sessions that used a LTE RAT. In someembodiments, the filter 320 may filter on a RAT type value specified inthe CDRs 116 that is indicative of whether an LTE RAT was used for acommunication session associated with the CDRs 116. For example, RATtype=6 may indicate an LTE RAT, whereas other RAT type values mayindicate other types of RATs (e.g., WiFi 2.0, GPRS Serving Node (GSN),Gateway GSN (GGSN), etc.). Accordingly, the filter 320 may filter theCDRs 116 by RAT type to obtain CDRs 116 that are based on LTE.

At 406, the filter 320 may select, from the first set of CDRs 116 thatremain after the filtering at 404 (i.e., the LTE-based CDRs 116), asecond set of CDRs 116 that are associated with communication sessionshaving a QCI value specified in the CDRs 116 that corresponds to VoLTE.In particular, the filtering at 406 may filter out LTE data traffic sothat the remaining CDRs 116 pertain to VoLTE (i.e., voice) traffic. Insome embodiments, the filter 320 may keep CDRs 116 specifying thatQCI=1, which ensures that the CDRs 116 remaining after the filtering at406 are those that are associated with communication sessions that usedVoLTE protocol.

At 408, the filter 320 may select, from the second set of CDRs 116 thatremain after the filtering at 406 (i.e., VoLTE-based CDRs 116), a thirdset of CDRs 116 that are associated with communication sessions havingcall durations specified in the CDRs 116 that are greater than athreshold period of time (e.g., greater than 0 seconds). The effect ofthe filtering at 408 is that individual ones of the CDRs 116 associatedwith calls that were made, but not completely answered, are removed fromconsideration. For example, if the UE 102 initiates a call to anotherUE, but the user of the UE 102 decides to hang up or otherwise stop thecall before it is answered, the CDR 116 associated with thatcommunication session (which would not have exceeded the thresholdperiod of time) can be filtered out at 408. One reason why it is usefulto filter out such CDRs 116 is because a certain AMR speech coding mode(e.g., AMR-WB 23.85 kbps) may be pre-negotiated for every VoLTE call,but after some re-negotiation (which may be based on the capabilities ofthe UE being called), the AMR speech coding mode that is designated forthe VoLTE call may comprise a narrow band coding mode (e.g., AMR NB 12.2kbps). Thus, the bandwidth indicated in a CDR 116 associated with acommunication session having a call duration less than the thresholdperiod of time may not accurately represent the codec that wouldotherwise have been established for the VoLTE call.

At 410, the filter 320 may select, from the third set of CDRs 116 thatremain after the filtering at 408 (i.e., CDRs 116 associated withcommunication sessions lasting longer than the threshold call duration),a fourth set of CDRs 116 associated with communication sessions thatwere released from a dedicated bearer of the communication sessionscorresponding to the fourth set of CDRs 116. Information pertaining towhether a VoLTE call was released from a dedicated bearer may bespecified in the CDR 116 for that VoLTE call, and as such, the filter320 may filter on this information to remove VoLTE calls that were notreleased properly. In other words, the filtering at 410 results in CDRs116 associated with communication sessions that were properly terminated(e.g., hung up) on the AMR codecs established for the communicationsessions. This ensures that the CDRs 116 remaining after the filteringat 410 are those CDRs 116 associated with calls that were establishedand the parties to the call actually talked over the established speechcodec.

At 412, the filter 320 may select, from the fourth set of CDRs 116 thatremain after the filtering at 410, a fifth set of CDRs 116 associatedwith communication sessions that were allocated an amount of bandwidthspecified in the CDRs 116 that is greater than a threshold bandwidth.The threshold bandwidth may be set at any suitable value. In someembodiments, the threshold bandwidth is set at 30000 bps, which ensuresthat CDRs 116 associated with communication sessions that were allocatedlesser bandwidth (e.g., communication sessions involving dual-tonemulti-frequency (DTMF) tones) are eliminated. The set of CDRs 116resulting from the process 400 comprise an example set of CDRs 116 thatmay be classified into groups based on allocated bandwidth and/or basedon the particular AMR speech coding mode utilized for the correspondingcommunication sessions.

FIG. 5 illustrates a flowchart of an example process 500 forestablishing correlations between AMR speech coding modes and bandwidthvalues. The process 500 may be implemented by the computing device(s)118 via the call tracer 316 to establish the correlations/mappings 126that are utilized in the process 120 of FIG. 1.

At 502, the call tracer 316 may trace a plurality of VoLTE calls, eachof the plurality of VoLTE calls using a known AMR speech coding mode.Any suitable tracing technique can be employed by the call tracer 316 at502, such as session analyzer software to extract relevant data from thesignals that are transmitted during a VoLTE communication session.

At 504, the call tracer 316 may extract, from a trace of the VoLTE call,an amount of bandwidth allocated for the VoLTE call. As noted above, theamount of bandwidth required for the created bearer traffic flow may becalculated by the PGW portion of the PGW/PCEF 218 of FIG. 2, such as byaggregating the requested bandwidth of all the GBR flows in the chargingrules created by the PCRF 212. This calculated bandwidth corresponds tothe bandwidth allocated for the communication session on the RANinterface between the UE 102 and the base station 104, and may be thebandwidth extracted by the call tracer 316 at step 504.

At 506, the known AMR speech coding mode for a VoLTE call may becorrelated with the amount of bandwidth extracted at 504 for the VoLTEcall in question, and the correlation may be stored in a data store(e.g., a database storing the mappings/correlations 126). In thismanner, a plurality of mappings 126 between AMR coding mode andbandwidth may be established for corresponding VoLTE calls that aretraced. In some embodiments, a correlation may be established between abandwidth value and an AMR speech coding mode after a threshold amountof VoLTE calls with that association have been traced using the process500. Setting a threshold number of VoLTE calls to establish amapping/correlation between an AMR speech coding mode and a particularbandwidth value may validate the relationship between the AMR speechcoding mode and the bandwidth value and may serve a quality controlfunction in that regard.

The environment and individual elements described herein may of courseinclude many other logical, programmatic, and physical components, ofwhich those shown in the accompanying figures are merely examples thatare related to the discussion herein.

The various techniques described herein are assumed in the givenexamples to be implemented in the general context of computer-executableinstructions or software, such as program modules, that are stored incomputer-readable storage and executed by the processor(s) of one ormore computers or other devices such as those illustrated in thefigures. Generally, program modules include routines, programs, objects,components, data structures, etc., and define operating logic forperforming particular tasks or implement particular abstract data types.

Other architectures may be used to implement the describedfunctionality, and are intended to be within the scope of thisdisclosure. Furthermore, although specific distributions ofresponsibilities are defined above for purposes of discussion, thevarious functions and responsibilities might be distributed and dividedin different ways, depending on circumstances.

Similarly, software may be stored and distributed in various ways andusing different means, and the particular software storage and executionconfigurations described above may be varied in many different ways.Thus, software implementing the techniques described above may bedistributed on various types of computer-readable media, not limited tothe forms of memory that are specifically described.

We claim:
 1. A computer-implemented method comprising: accessing a firstdatabase of call detail records (CDRs) containing information associatedwith a plurality of communication sessions established over a mobiletelephony network; selecting, from the CDRs, a first set of CDRs thatare associated with communication sessions that used a long termevolution (LTE) radio access technology (RAT); selecting, from the firstset of CDRs, a second set of CDRs that are associated with communicationsessions having a Quality of Service Class Indicator (QCI) value thatcorresponds to voice over long term evolution (VoLTE); selecting, fromthe second set of CDRs, a third set of CDRs that are associated withcommunication sessions having durations greater than a threshold periodof time; selecting, from the third set of CDRs, a fourth set of CDRsassociated with communication sessions that were released from a bearerof the communication sessions corresponding to the fourth set of CDRs;selecting, from the fourth set of CDRs, a fifth set of CDRs associatedwith communication sessions that were allocated an amount of bandwidthgreater than a threshold bandwidth; referencing a second databasecontaining correlations between adaptive multi-rate (AMR) speech codingmodes and bandwidth values; classifying the CDRs of the fifth set ofCDRs into groups of different AMR speech coding modes based at least inpart on the referencing; and recommending a capacity planning metric ora resource allocation metric based at least in part on the classifying.2. The computer-implemented method of claim 1, further comprising, priorto referencing the second database, creating the correlations in thesecond database by: tracing a plurality of VoLTE calls, each of theplurality of VoLTE calls using a known adaptive multi-rate (AMR) speechcoding mode; for each of the plurality of VoLTE calls: extracting, froma trace of the VoLTE call, an amount of bandwidth allocated for theVoLTE call; and correlating the known AMR speech coding mode with theamount of the bandwidth allocated for the VoLTE call.
 3. Thecomputer-implemented method of claim 1, further comprising determining asixth set of CDRs associated with one or more groups of the groups ofdifferent AMR speech coding modes that are based on an AMR Wideband (WB)codec, wherein the capacity planning metric or the resource allocationmetric is based at least in part on a number of the CDRs in the sixthset of CDRs.
 4. The computer-implemented method of claim 1, wherein theresource allocation metric comprises a recommended amount of bandwidthfor serving customers of the mobile telephony network over a futureperiod of time and a recommended number of available resources forproviding the recommended amount of bandwidth.
 5. Thecomputer-implemented method of claim 1, wherein the selecting the firstset of CDRs comprises filtering the CDRs by a RAT type value thatcorresponds to the LTE RAT.
 6. The computer-implemented method of claim1, wherein the threshold bandwidth is about 30,000 bits per second(bps).
 7. A computer-implemented method comprising: accessing aplurality of call detail records (CDRs) containing informationassociated with a plurality of corresponding communication sessionsestablished over a mobile telephony network; filtering the plurality ofCDRs to obtain a subset of CDRs that are associated with communicationsessions that used voice over long term evolution (VoLTE) services;referencing a data structure containing correlations between adaptivemulti-rate (AMR) speech coding modes and bandwidth values; classifyingthe CDRs of the subset of CDRs into groups of different AMR speechcoding modes based at least in part on the referencing; and recommendinga capacity planning metric or a resource allocation metric based atleast in part on numbers of the CDRs in the subset of CDRs within eachof the groups of the different AMR speech coding modes.
 8. Thecomputer-implemented method of claim 7, wherein filtering the pluralityof CDRs comprises: filtering the plurality of CDRs by a radio accesstechnology (RAT) type value that corresponds to a long term evolution(LTE) RAT.
 9. The computer-implemented method of claim 7, whereinfiltering the plurality of CDRs comprises: filtering the plurality ofCDRs by a Quality of Service Class Indicator (QCI) value thatcorresponds to voice over long term evolution (VoLTE).
 10. Thecomputer-implemented method of claim 7, wherein filtering the pluralityof CDRs comprises: filtering the plurality of CDRs by session durationsuch that the subset of CDRs is associated with communication sessionshaving durations greater than a threshold period of time.
 11. Thecomputer-implemented method of claim 7, wherein filtering the pluralityof CDRs comprises: filtering the plurality of CDRs by informationindicating a successful bearer release such that the subset of CDRs isassociated with communication sessions that were released from a bearerof the communication sessions.
 12. The computer-implemented method ofclaim 7, wherein filtering the plurality of CDRs comprises: filteringthe plurality of CDRs by bandwidth allocation such that the subset ofCDRs is associated with communication sessions that were allocated anamount of bandwidth greater than a threshold bandwidth.
 13. Thecomputer-implemented method of claim 7, further comprising, prior toreferencing the data structure, creating the correlations in the datastructure by: tracing a plurality of VoLTE calls, each of the pluralityof VoLTE calls using a known adaptive multi-rate (AMR) speech codingmode; for each of the plurality of VoLTE calls: extracting, from a traceof the VoLTE call, an amount of bandwidth allocated for the VoLTE call;and correlating the known AMR speech coding mode with the amount of thebandwidth allocated for the VoLTE call.
 14. One or more non-transitorycomputer-readable media storing computer-executable instructions that,when executed, cause one or more processors of a mobile device toperform acts comprising: accessing a plurality of call detail records(CDRs) containing information associated with a plurality ofcorresponding communication sessions established over a mobile telephonynetwork; filtering the plurality of CDRs to obtain a subset of CDRs thatare associated with communication sessions that used voice over longterm evolution (VoLTE) services; referencing a data structure containingcorrelations between adaptive multi-rate (AMR) speech coding modes andbandwidth values; classifying the CDRs of the subset of CDRs into groupsof different AMR speech coding modes based at least in part on thereferencing; and recommending a capacity planning metric or a resourceallocation metric based at least in part on numbers of the CDRs in thesubset of CDRs within each of the groups of the different AMR speechcoding modes.
 15. The one or more non-transitory computer-readable mediaof claim 14, wherein filtering the plurality of CDRs comprises:filtering the plurality of CDRs by a radio access technology (RAT) typevalue that corresponds to a long term evolution (LTE) RAT to obtain afirst set of CDRs; filtering the first set of CDRs by a Quality ofService Class Indicator (QCI) value that corresponds to voice over longterm evolution (VoLTE) to obtain a second set of CDRs; filtering thesecond set of CDRs by session duration to obtain a third set of CDRsassociated with communication sessions having durations greater than athreshold period of time; filtering the third set of CDRs by informationindicating a successful bearer release to obtain a fourth set of CDRsassociated with communication sessions that were released from a bearerof the communication sessions; and filtering the fourth set of CDRs bybandwidth allocation to obtain a fifth set of CDRs associated withcommunication sessions that were allocated an amount of bandwidthgreater than a threshold bandwidth.
 16. The one or more non-transitorycomputer-readable media of claim 15, wherein the threshold bandwidth isabout 30,000 bits per second (bps).
 17. The one or more non-transitorycomputer-readable media of claim 14, the acts further comprisingdetermining a sixth set of CDRs associated with one or more groups ofthe groups of different AMR speech coding modes that are based on an AMRWideband (WB) codec, wherein the capacity planning metric or theresource allocation metric is based at least in part on a number of theCDRs in the sixth set of CDRs.
 18. The one or more non-transitorycomputer-readable media of claim 14, wherein the resource allocationmetric comprises a recommended amount of bandwidth for serving customersof the mobile telephony network over a future period of time and arecommended number of available resources for providing the recommendedamount of bandwidths.
 19. The one or more non-transitorycomputer-readable media of claim 14, wherein the capacity planningmetric comprises a recommended number of new resources for providingservice to customers of the mobile telephony network.
 20. The one ormore non-transitory computer-readable media of claim 14, the actsfurther comprising, prior to referencing the data structure, creatingthe correlations in the data structure by: tracing a plurality of VoLTEcalls, each of the plurality of VoLTE calls using a known adaptivemulti-rate (AMR) speech coding mode; for each of the plurality of VoLTEcalls: extracting, from a trace of the VoLTE call, an amount ofbandwidth allocated for the VoLTE call; and correlating the known AMRspeech coding mode with the amount of the bandwidth allocated for theVoLTE call.